Derivative Instruments (Outstanding Foreign Currency Forward Contracts) (Details) (USD $) In Thousands, unless otherwise specified	Aug. 31, 2012	Nov. 30, 2011
Derivative [Line Items]
Total, Notional Value	$ 26,221	$ 38,455
Total, Fair Value	(88)	52
Forward contracts to sell U.S. dollars [Member]
Derivative [Line Items]
Foreign currency derivative contracts to sell U.S. dollars, Notional Value	5,773	2,180
Foreign currency derivative contracts to purchase U.S. dollars, Fair Value	(16)	(54)
Forward contracts to purchase U.S. dollars [Member]
Derivative [Line Items]
Foreign currency derivative contracts to purchase U.S. dollars, Notional Value	20,448	36,275
Foreign currency derivative contracts to purchase U.S. dollars, Fair Value	$ (72)	$ 106